Railway-traffic-controlling apparatus



Aprilzs, 1931- R. A. M CANN RAILWAY TRAFFIC CONTROLLING APPARATUS Filed March 18, 1930 K MWWHM s \TLL E w m, fi nldw lllF' ww F3 F7 R Unit RONALD A. BEQ'CA'NN F SWISSVALE, PENNSYLVANIA, ASSTGNOR TO THE UNION SWITCH & SIGNAL COMPANSLOF SWISSVALE PENNSYLVANIA, A. CORPORATION OF PENN- SYLVANIA RAILWAY-ERA EPIC-CONTROLLING APPARATUS Application 'filed March 18, 1380; Serial No. 436,753.

My inventionrelates to railway traffic controlling apparatus, and particularly to apparatus of the type involving a railway switch together with signals governing traffic over t ie switch, which switch and signals are controlled from a distant point such as a despatchers oiiice. One feature of my invention is the provision of novel and improved means for controlling the approach locking of the switch in systems of this character.

I will describe one form of apparatus em bodying my invention, and will then point out the novel features thereof in claims.

The accompanying drawing is a diagram- 15 matic view showing one form of apparatus embodying my invention. 7 Referring to the drawing, the reference characters 1 and 1 designate the track rails of'a stretch of railwaytrack whichI'will call the main track. These rails are divided by insulated joints 2 to form three track secions AB, BC and CD, of which the middle section may be termed the main section, and the two outer sections may be termed approach sections. Located in the main section 13-0 is a switch E, which when reversed, diverts trafic from the main track into a side track Z. r

Each section of the main trackis provided with the usual track circuit comprising a battery 3' and a trackrelazy designated Twith a distinguishing exponent. The track circuit for the main section B-C is'extended in the usual way to the fouling point of the side track Z.

The switch E is provided with an operating mechanism 13 which is controlled by a switch relay G, and which relay in turn is controlled by a switch lever L located at a remote point, such for example, as a despatchers oifice. The control of the switch mechanism F by a neutral contact 55 and polar contacts 8 and 9 of relay G is standard in every respect and requires no detailed expl'anation. The circuit forrelay G passes from terminal X of a suitable source of current through contact of lever L winding of relay G, front contact 44 of a master relay M, front contact 27 of track relay T and contact 50f lever. L to terminal 0 of the same source of current. The current thus supplied to relay G is of normal or reverse polarity according as lever L is in the normal or the reverse position, and, consequently, switch E will occupy its normal or its reverse position according to the position of the controlling lever. It will be noted that the circuit for'relay G- can not be closed unless track section BC is unoccupied, and unless the master relay M is energized. Trai'iic moving toward the right into section B C is governed by two signals S and 8%, which signals are controlled by signal relays E and HR; in accordance with the usual practice. Traiiic on the main track moving toward the left into section'B C is governed by a signal S which is controlled by'a signal relay H and trafiic moving in the same direction on the side track Z is con trolled by a signal S which is in turn controlled by a signal relay H The signal relays H are controlled by a main signal relay J, and the relay J is controlled by a lever L located in the despatchers ofiice. This lever is provided with pole changing contacts 6 and 7 which operate in the usual manner to sup ply current of normal or reverse polarity to relay J according as the lever is moved to its right hand position or its left-hand position. lVh'en relay J is energized in the normal direction, relay H or relay H will be energized according as switch E is in the normal or the reverse position, this selection as to relays being determined in the usual manner by a circuit controller W operatively connected with the switch. It follows that sig nal S or signal 8% will then be cleared, depending upon the position of the switch. Similarly, when relay J is ener ized in the reverse direction, signal S or S willbe clear according as the switch is in the normal or the reverse position. The circ uit for each of the relays H includes a front contact, such as T of track'relay T, the purpose of which is to prevent any one of the signals from indicating clear when the main section BC is occupied, and to cause any signal which has been cleared to return to the stop position when atrain enters this section. The control Ofthe signals governing traflic over the switch E is normal and standard in every respect and requires no detailed tracing of circuits.

The apparatus includes an eastbound approach relay P and a westbound approach relay P Relay P is provided with a pickup circuit which includes front contact 22 of track relay T and front contact 25 of relay T and relay P is also provided with a stick circuit which includes contact 22 of relay T and contact 3? of relay P but ex eludes contact 25 of track relay T It follows that relay P will be energized when sections AB and BC are both unoccupied, but that it will become deenergized when a t ain moving toward the right enters section A-B and will remain deenergized until such train leaves section BC.

The westbound approach relay P is controlled in a similar manner by track relays T and T for sections CD and B-G, respectively, so that relay P is normally energized but will become deenergized when a train moving toward the left enters section CD, and will remain deenergized until such train leaves section B-C.

he master relay M is controlled in part by an auxiliary master relay Q. Relay Q is provided with a pick-up circuit which passes from terminal X, through back contacts 28, 30, 32 and 34 of the H relays, back contact 42 of relay P back contact 26 of relay T back contact 39 of relay P and the winding of relay Q, to terminal O. It follows that in so far as this pick-up circuit is concerned, relay Q can become energized when and only when all of the signals indicate stop, both approach relays P are deenergized, and track relay T is likewise deenergized. Relay Q is provided. with a stick circuit which includes the back contacts of the H relays but which passes from back contact 34, through front contact 45 of relay Q, and the winding of this relay to terminal 0. In other words, this stick circuit includes the back contacts of all of the H relays but excludes the back contacts of the P relays and of track relay T It follows that when relay Q once becomes energized it will remain energized as long all of the signals remain in the stop positions. When relay Q, is closed, a pick-up circuit for relay M becomes closed, which circuit passes from terminal K, through back contact 5 of a relay U, front contact 47 of relay Q- and the winding of relay M to terminal 0. Relay M is provided with a main stick circuit which passes from terminal X,

through back contact 35 of signal relay H back contact 33 of relay H ,back Contact 31 of relay H back contact 29 of relay H front contact l3 of relay M, and the winding of relay M to terminal 0. This circuit is provided with a branch around contact 33 i which includes front contact 41 of the westbound approach relay P It is also provided with a branch around back contacts 31 and 29 of the eastbound signal relays, whichbranch includes contact 38 of eastbound approach relay P The stick circuit for relay M and the branches for this stick circuit are in accordance with standard and usual practice and form no part of my present inven tion.

The pick-up circuit for relay Q is provided with another branch around contacts 42, 26 and 39, which branch includes a normally open, slow-acting device V, whereby after a given interval of time relay Q, may be energized even though one of the relays P P or T is closed, provided, of course, that all of the signal relays H are open.

The pick-up circuit for relay Q, is provided with a third branch around contacts 12, 26 and 39, which branch includes front contact 53 of a normally deenergized relay U. The function and operation of relay U will be explained hereinafter.

I will now assume that the parts of the apparatus are in the positions in which they are shown in the drawing, and that the despatcher desires to admit a train moving toward the right into section BC. To do this, he will move signal lever L to the right, thereby clearing signal S When the train enters the approach section A-B, it will deenergize the approach relay P and inasmuch as signal relay H is energized, the stick circuit for relay M will be opened and so this relay will release. When the train enters section BC, it will open track relay T but approach relay P will remain closed, and, consequently, relay Q will not become energized. When the forward end of the train enters section CD, relay P will become deenergized, whereupon, the main pickup circuit for relay Q will become closed. This relay will then close the Pick-up circuit for relay M, thereby releasing the approach locking of the switch E.

I will now assume that while the train moving toward the right is in section AB the despatcher desides that he wants to reverse switch E. To do this, he will restore signal S to the stop position, whereupon, it will be necessary to operate the slowacting circuit controller V to close the pick-up circuit for relay Q, and when relay Q becomes energized it will cause relay M to become energized as before.

The apparatus thus far described has two important characteristics. One is that a light engine or other vehicle of a length not sufficient to simultaneously deenergize all three of the track relays T will, nevertheless, re-

lease the approach locking, because after such vehicle enters either of the approach sections, such as section A-B, the approach relay P will remain deenergized until the other approach relay P becomes deenergized, whereby the main pick-up circuit for relay Q will be closed when the vehicle bridges the insulated joints between sections B-C and CD. The othe important characteristic is that if the-track circuit current for section BC is momentarily interrupted while a train in either of the approach sections, the approach locking will not' be released, be cause the main pick-up circuit for relay will not become closed during suchmomentary interruption of track circuit current.

The function of relay U is to provides. time interval before the approach locking will be released in the event that signal 3 3 is cleared and is then returned to the stop position before it'is acceptedsby a train; When signal S is cleared, that is, when relay H is energized, a pick-up circuit for a relay R will become closed through the front point of contact 36 of relay H This will close a stick circuit for relay R, which includes front contact 49 of relayR and back contact 46 of relay Q. Then when relay H becomes deenergized, a heatingaelement 51 of a thermosensitive relay Y will be'supplied with currentthrough the back point of contact 36 of relay H and front contact 50 of relay B. After a given interval of time, the thermosensitive relay Y will close itsnormally' open contact 52, thereby energizing relay U. The third branchfor the pick-upcircuit of relay Q will then be closed through front contact :58 )f relay U, with theresult that relay Q, willbe come energized. As soon as relay Q closes, it will open at contact 46 the stick circuit for relay R, and this relay will open at contact 50 the circuit for the heating element 51, with the result that contact 52 will open and relay U will become deenergized. When relay U releases, the pick-up circuit for relay lil will become closed through back contact 5140f relay U a-nd front contact 47 of relay Q, so that relay M will pick up and will release the approach locking for switch E.

Switch E is provided with a switch repeater relay K which is controlled in the usual manner by pole changing contacts 56 forming part of the switch circuit controller TV. Polar contact 48 of relay K is open or closed according as switch E is in the normal or the reverse position. Nhen contact 48 is closed, it closes a shunt around back contact 42 of the westbound approach relay P and so it follows that when the switch E is re versed and a train moving toward the right enters the side track Z, relay Q, will become energized when the train passes the fouling point of this side tr ck, even though such train will not enter section C-D and so will not cause relay P to be deenergized.

Although I have herein shown and described only one form of apparatus embodying my invention, it is understood that various changes and modifications may be made therein within the scope of the appended claims without'departing from the spirit and scope of my invention. c

Having thus described my invention, what Iclaiinis:

1. In combination, a stretch of, railway track divided llOifOllll a main section BC and two approach sections A.B and CD on opposite sides of'the main section, a track relay foreach of said sections, a. switch leading from section B-C into a side track, signals governingtraific into said main section B-C, signal relays for the control ofsaid signals, an approach relay l? provided with a. pick-up circuit including front contacts of the trackrelays for sections AB and BC and a stick circuit including a front contact of the former track relay but not of the latter, an approach relay controlled in similar manner by the track relays for sections G-D and BC, an approach locking relay M, an auxiliary approach locking relay Q, a pick-up circuit for relay Q including back contacts of said approach relays and back contact of the track relay for section B-(l as well as backcoiitacts of said signal relays, a stick circuit for relay Q, including back contacts ofsaid signal relays, a pick-up cir: cuit for relay M including a front contact of relay Q, a stick circuit for relay M controlled in the usual manner by said track and approach relays, and means for preventing operation'of said switch unless relay M is closed. c c

2. In combination, a stretch of railway track divided to form a main section B-C and two approachsections r B and GD on opposite sides of the main section, a track relay for each of said sections, a switch lead ing from section BG into a side track, signals governing traffic into said main sections B.C, signal relays for the controlof said signals, an approach relayl provided with a pick-up circuit including front contacts of the track-relays for sections A-Band B-C and a stick circuit including a front contact of the former track relay but notof the latter, an approachrelay controlled in simiin manner by the track relays for sections 0-D and B-C, an approachlocking relay M, an'auxiliary approach locking relay Q, a pick-up circuit for relay Q, including back contacts'of said approach relays and aback contact of the track relay for section B'C as well as backcontacts of'said signal relays, a stick circuit for relay Q including back contacts of said signal relays, a relay R, a pick-up circuit for relay R including a front contact of the signal relay for the signal governing trafficfrom said side track into section 3-6, a stick circuitfor relay R- in eluding-a back contact of relay. Q, a slowacting thermo-sensitive relayhaving aheatingelement and anormally open contact 52, a circuit for said heating element'including a back contact of said last mentioned signal relay and a front contact of relay R, an auxiliary relay U controllel by said contact 52, an auxiliary pick-up circuit for relay Q including a front contact of relay U and back contacts of said signal relays, a pick-up circuit for relay M including a front contact of relay Q: and a back contact 'of relay U, a tick circuit for relay M controlled in the usual manner by said track and approach relays, and means for preventing operation of said switch unless relay M is closed.

3. In combination, a stretch of rainvay track divided to form a main section B-C and two approach sections A-B and C D on opposite sides of the main section, a track relay for each of said sections, a switch leading from section B-C into a side track, signals governing traiiic into said main section BC, signal relays for the control of said si nals an a roach rela 1 P provided with a pick-up circuit includi front contacts of the track relays for sections AB and BC and a stick circuit including a front contact of the former track relay but not of the latter, an approach relay controlled in similar manner by the track relays for sections CD and 13-6, and approach locking means for said switch controlled by said approach, signal and track relays. 7

4:. In combination, a section of railway track divided to form a main section and an approach section, a track relay for each of said sections, a switch leading from said main section into a side track, an approach relay having a pick-up circuit including a front contact on each of said track relays, a-sticlr circuit for said approach relay including a front contact of the track relay for the approach section but not a contact'of the other track relay, and approach locking means for said switch controlled in part by said approach relay and the track relay for the main section.

5. In combination, astretchof railway track I divided to form a main section B@ and two approach sections AB and CD on opposite sides of the main section, a tracl: relay for each of said sections, a switch leading from sections BC into a side track, signals governing traflicinto said main section BC, an approach relay P means for energizing relay P requiring that the track relaysfor sections A-B and B-C be closed and for subsequently keeping it energized as long as the track relay for section A-B remains closed, an approach relay P controlled in similar manner by the track relays for sections CD and B-C, an approach locking relay M, an auxiliary approach locking relay Q, means for cnergizi relay Q provided that all of said signals are at stop and both of said approach relays and the track relay for section B C are open, means for subsequently keeping relay Q, closed as long as all of said signals remain at stop, means for energizing relay M when relay Q, is energized and for subsequently keeping it energized until a train approaches a cleared signal, and means for preventing operation of said switch unless relay d is closed. I

6. In combination, a stretch of railway track divided to form a main section BC and two approach sections A and CD on opposite sides of the main section, a track relay for each of said sections, a switch leadingfrom section BC into a side track, signals governing traffic into said main section B-C, an approach relay P means for energizing relay P requiring that the track relays for sections A-B and BC be closed and for subsequently keeping it energized as long as the track relay for section A.l3 re mains closed, an approach relay P controlled in similar manner by the track relays for sections (1 1) and 3-0, an approach looking relay M, an auxiliary approach locking relay Q, means for energizing relay Q provided that all of said signals are at stop and both of said approach relays and the track relay for section BC are open, means for subsequently keeping relay Q closed as long as all of said siqnals remain at stop, means for energizing relay M when relay Q is energized and for subsequently keeping it energized until the signal governing traiiic into section B-Gfrom said side track is cleared or until a train approaches any of the other signals, when indicating clear, auxiliary means for energizing relay Q after a given time interval following the return to stop of said signal governing trailic from the side track, and means for preventing operation of said switch unless relay M is closed.

In testimony whereof I affix my signature.

RONALD A. MGCANN. 

